1. Field of the Invention
This invention relates generally to fastener installation tools for automatically crimping a nut onto a bolt forming a lock-bolt combination in a fastener assembly, and more particularly to apparatus generally referred to as a nose assembly for receiving the nut and bolt combination in a substantially tubular housing having means to secure and apply an axial force to the nut and bolt assembly for swaging the nut onto the bolt forming a fastener combination.
2. Description of the Prior Art
Conventionally, two or more workpieces may be secured together with a lock-bolt type combination, whereby a nut or collar is swaged onto a cylindrical pin or bolt by the crimping action of an axial force applied by an installation tool. The locking nut or collar is engaged by an apparatus generally referred to as a nose assembly which is part of a hydraulic or pneumatic pull-type installation tool well-known in the art. The effect of the crimping is to cause a portion of the counterbore of the nut to be forced into locking grooves on the bolt and to effect an elongation of the nut which places the bolt under high residual tension.
Conventional pull gun assemblies, commonly referred to as installation tools or guns are generally well known in the art, and may be modifications of the type described in U.S. Pat. No. 2,132,112 issued to L. C. Huck. Many modifications of the concept for the installation tool for swaging collars onto the threaded bolts have been proposed such as that shown in U.S. Pat. No. 3,329,000 issued to C. J. Schwab, et al and that is shown in U.S. Pat. No. 3,722,329 issued to Van Hecke, et al. These installation tools generally have what is commonly referred to as a nose assembly which houses an anvil member which performs the crimping function and also a means to grip the pin of the fastener. The pin or bolt is pulled by pull a piston in response to a hydraulic or pneumatic action such that the collar or nut is swaged by the anvil onto the bolt.
These nose assemblies must be changed to accommodate different bolt diameters and lengths for various lock-bolt applications. In assembly operations, such as aircraft construction, an operator may be required to install as many as 15 different types of lock-bolt combinations in an assembly process. This requires that the operator have 15 different installation available for each lock-bolt size or lose time in the assembly process while the nose assemblies are changed over for performing the different lock-bolt operations.
It would be desirable if there were provided an installation tool or gun that had means for providing a quick change of the nose assembly by the operator without the need for special tooling or lost time taking the tool out of service for changeover operations.
It is an object of this invention to provide an improved nose assembly which is actuated by the conventional pull type installation tool or gun with a feature that allows a operator to quickly change the nose assembly to accommodate different lock-bolt type specifications.